1. Field of the Invention
This invention relates to shoe machines and more particularly to shoe machines having adjustable tensioning devices therewith.
2. Prior Art
In the manufacture of shoes utilizing conventional shoe lasting machines, shoe uppers have to be pulled snugly over lasts utilizing tensioning devices which have to be held in adjusted position by an operator for the duration of the pulling over operation. This pulling over operation is usually terminated by the marginal portions of the upper being secured to the insole either at selected points or by lasting the marginal portions of the upper with respect to the last. Holding these tensioning devices is a very inconvenient operation for the operator to perform especially when he wishes to vary the tension in one or more localities utilizing one or more grippers on a particular side of the shoe being lasted.
In order to overcome this inconvenience, it has been proposed to provide means for locking the tensioning devices in a particular adjusted position. One such device included a ratchet-and-pawl arrangement. This method is not completely satisfactory because the adjustments must be made stepwise, which is not always smooth and easy, and the release of such an arrangement generally is very complicated.
It is an object of the present invention to provide a shoe lasting machine wherein the action of the tensioning devices is infinitely variable, and wherein such devices can be utilized in a locked-in adjusted position.